Endocrine Abstracts

Introduction: Vein of Galen (VoGM) is a rare intracerebral vascular anomaly which may be detected on antenatal imaging or present in the neonatal period with secondary cardiac failure. A potential association with congenital hypothyroidism was examined.

Investigation: Between the seven months of October 2015 and May 2016 six infants with VoGM were treated at our tertiary centre. Three (50%) were also referred through Congenital Hypothyroidism (CHT) Newborn Screening. These infants had borderline blood spot TSH concentrations ranging from 10–17 mU/l thus requiring a second screening card before referral to the CH service. Venous TSH concentrations ranged 17–44 mU/l (normal range <6). Two babies had low thyroxine hormone concentrations and all three required treatment with Levothyroxine.

All infants underwent technetium imaging and all had a normally located and shaped thyroid gland with avid tracer uptake, suggesting a diagnosis of CHT due to dyshormonogenesis. Initial starting doses of Levothyroxine were 25 micrograms daily (range between 8.6–10.5 mcg/kg/day). One infant required a dose reduction to 20 micrograms daily. Thyroid function normalised within 13–20 days of starting treatment. Of the three VoGM infants who were not referred through CH screening, one had normal thyroid function and the thyroid status of the two other infants is unknown.

Review of the CHT service records from 2006, identified three further infants with VoGM. Two of these infants required treatment with Levothyroxine. One infant died at a month of age and the second infant had a transient form of CHT and stopped treatment at 2 years of age.

Conclusion: This is the first report of an association between CHT and VoGM and would suggest that checking thyroid function in these infants would be advisable so that monitoring and early initiation of treatment with Levothyroxine can occur if indicated. An association between vascular malformations and hypothyroidism has been previously attributed to an excess of Type 3 diodinase. It is possible that a similar process may occur in VoGM. Further investigation is warranted.